const {ccclass, property} = cc._decorator;
declare function unescape(s: string): string;

@ccclass
export class base64 {
        public static hexToBytes(hex) {
            for (var bytes = [], c = 0; c < hex.length; c += 2)
                bytes.push(parseInt(hex.substr(c, 2), 16));
            return bytes;
        }
        public static bytesToHex(bytes) {
            for (var hex = [], i = 0; i < bytes.length; i++) {
                hex.push((bytes[i] >>> 4).toString(16));
                hex.push((bytes[i] & 0xF).toString(16));
            }
            return hex.join("");
        }
        public static b64tohex(str) {
            for (var i = 0, bin = atob(str.replace(/[ \r\n]+$/, "")), hex = []; i < bin.length; ++i) {
                var tmp = bin.charCodeAt(i).toString(16);
                if (tmp.length === 1) tmp = "0" + tmp;
                hex[hex.length] = tmp;
            }
            return hex.join("");
        }
        public static addPreZero(num, length) {
            var t = (num + '').length,
                s = '';
            for (var i = 0; i < length - t; i++) {
                s += '0';
            }

            return s + num;
        }
        // private method for UTF-8 encoding
        public static _utf8_encode(string) {
            string = string.replace(/\r\n/g, "\n");
            var utftext = "";
            for (var n = 0; n < string.length; n++) {
                var c = string.charCodeAt(n);
                if (c < 128) {
                    utftext += String.fromCharCode(c);
                } else if ((c > 127) && (c < 2048)) {
                    utftext += String.fromCharCode((c >> 6) | 192);
                    utftext += String.fromCharCode((c & 63) | 128);
                } else {
                    utftext += String.fromCharCode((c >> 12) | 224);
                    utftext += String.fromCharCode(((c >> 6) & 63) | 128);
                    utftext += String.fromCharCode((c & 63) | 128);
                }

            }
            return utftext;
        }
        // private method for UTF-8 decoding
        public static _utf8_decode(utftext) {
            var string = "";
            var i = 0;
            var c = 0, c1 = 0, c2 = 0;
            while (i < utftext.length) {
                c = utftext.charCodeAt(i);
                if (c < 128) {
                    string += String.fromCharCode(c);
                    i++;
                } else if ((c > 191) && (c < 224)) {
                    c1 = utftext.charCodeAt(i + 1);
                    string += String.fromCharCode(((c & 31) << 6) | (c1 & 63));
                    i += 2;
                } else {
                    c1 = utftext.charCodeAt(i + 1);
                    c2 = utftext.charCodeAt(i + 2);
                    string += String.fromCharCode(((c & 15) << 12) | ((c1 & 63) << 6) | (c2 & 63));
                    i += 3;
                }
            }
            return string;
        }

        public static base64_encode(input) {
            var _keyStr = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";

            var output = "";
            var chr1, chr2, chr3, enc1, enc2, enc3, enc4;
            var i = 0;
            input = this._utf8_encode(input);
            while (i < input.length) {
                chr1 = input.charCodeAt(i++);
                chr2 = input.charCodeAt(i++);
                chr3 = input.charCodeAt(i++);
                enc1 = chr1 >> 2;
                enc2 = ((chr1 & 3) << 4) | (chr2 >> 4);
                enc3 = ((chr2 & 15) << 2) | (chr3 >> 6);
                enc4 = chr3 & 63;
                if (isNaN(chr2)) {
                    enc3 = enc4 = 64;
                } else if (isNaN(chr3)) {
                    enc4 = 64;
                }
                output = output + _keyStr.charAt(enc1) + _keyStr.charAt(enc2) + _keyStr.charAt(enc3) + _keyStr.charAt(enc4);
            }
            return output;
        }

        // public method for decoding
        public static base64_decode(input) {

            var _keyStr = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";

            var output = "";
            var chr1, chr2, chr3;
            var enc1, enc2, enc3, enc4;
            var i = 0;
            input = input.replace(/[^A-Za-z0-9\+\/\=]/g, "");
            while (i < input.length) {
                enc1 = _keyStr.indexOf(input.charAt(i++));
                enc2 = _keyStr.indexOf(input.charAt(i++));
                enc3 = _keyStr.indexOf(input.charAt(i++));
                enc4 = _keyStr.indexOf(input.charAt(i++));
                chr1 = (enc1 << 2) | (enc2 >> 4);
                chr2 = ((enc2 & 15) << 4) | (enc3 >> 2);
                chr3 = ((enc3 & 3) << 6) | enc4;
                output = output + String.fromCharCode(chr1);
                if (enc3 != 64) {
                    output = output + String.fromCharCode(chr2);
                }
                if (enc4 != 64) {
                    output = output + String.fromCharCode(chr3);
                }
            }
            output = this._utf8_decode(output);
            return output;
        }
}